Lower facial remodeling with botulinum toxin type A for the treatment of masseter hypertrophy

BACKGROUND

Masseter hypertrophy has been treated with botulinum toxin injections because ofesthetic complaints especially in Asians.

OBJECTIVES

The goal of the present study was to evaluate the efficacy of abobotulin toxin usein masseter hipertrophy treatment in Brazilians.

METHODS

Ten Brazilian female patients with masseter hypertrophy were subjected toinjections of 90U of abobotulinum toxin A applied on each side respecting thesafety zone stabilished in literature and were followed up for 24 weeks.

RESULTS

When analyzing the coefficients between measures of middle and lower third of theface obtained from standardized photographs, an increase was observed, withstatistical significance at 2 weeks (p=0.005) and 12 weeks (p=0.001). Theprogression of lower third reduction was 3.94%, 5.26%, 11.99%, and 5.47% (2, 4,12, and 24 weeks respectively). All patients showed improvement in bruxism aftertreatment. Observed adverse effects were masticatory fatigue, smile limitation,and smile asymmetry.

CONCLUSION

The use of abobotulinum toxin A for masseter hypertrophy is effective inBrazilians and reached its maximum effect of facial thinning at 12 weeks. Smilelimitation had a higher incidence compared to that reported in the literature andmay result from risorius muscle blockage caused by toxin dissemination. Despiteits side effects, 80% of the patients would like to repeat the treatment.